Originally Posted by Molly's_Mommy
Molly has been on a diet of Purina kitten chow, ever since she came to live with me(six months ago). It was about a 3-4 weeks ago, I started her on Fancy Feast along with her regular food has a treat. It seems as if her ulcers happened around the same time.
What flavours of Fancy Feast? There are quite a few ingredients in some of the FF varieties that can be hyperallergenic to cats. Fish is a big one, as are wheat gluten, soy, beef, and "mystery meat" by-products. The Purina Kitten Chow isn't that great either, so my recommendation is to find a grain-free canned food (or else consider a raw diet) with a novel protein source (and no fish). Innova Evo 95% makes venison or duck, and Nature's Variety Instinct also has rabbit, if you can find it. If neither of these are available in your area, maybe Natural Balance Venison or Duck and Green Pea is.
What kind of dishes does Molly eat/drink out of? If they're plastic, that could also be part of the problem. Switching to glass or stainless steel would be better.
Some info for you on why cats should only eat wet food: www.catinfo.org